Locking devices for movable pin-shaped electrical contacts

ABSTRACT

A plug device for engaging a cooperating device for transferring electrical current in which one or more pairs or pins are supported by a housing with one pin of each pair being fixed relative to the housing and one end portion of both pins being engagable with the cooperating plug device. A fulcrum point is established for the other pin of each pair, with the latter being engaged by an actuation lever for urging the one end portion thereof about said fulcrum point in a direction away from the one end portion of the other pin to increase the contact pressure with the corresponding plug device.

United States Patent 1191 Louis LOCKING DEVICES FOR MOVABLE PIN-SHAPED ELECTRICAL CONTACTS 1 Dec. 10, 1974 3,374,455 3/l968 Sullivan et al 339/255 P Primary Examiner-Joseph H. McGlynn Attorney, Agent, or FirmLanc, Aitken, Dunner & Ziems [57] ABSTRACT A plug device for engaging a cooperating device for transferring electrical current in which one or more pairs or pins are supported by a housing with one pin of each pair being fixed relative to the housing and one end portion of both pins being engagable with the cooperating plug device. A fulcrum point is established for the other pin of each pair, with the latter being engaged by an actuation lever for urging the one end portion thereof about said fulcrum point in a direction away from the one end portion of the other pin to increase the contact pressure with the corresponding plug device.

4 Claims, 13 Drawing Figures position selected is carried out by cooperation of at least one resilient receptacle contact with a recess formed in the internal face of said safety disc.

4. An electric connection device as claimed in claim 1 and comprising four poles in which the angular displacement (1) between two consecutive angular positions of a contact support with respect to the guiding means is 15 whilst the three phase contacts are disposed at intervals along their positionlocation circumference starting from the neutral at locations of 90, 180 and 285 in the reverse direction.

5. An electric connection device as claimed in claim 4, wherein the safety disc is provided with six openings 7. An electric connection device as claimed in claim 5, wherein said safety disc is rotatable between each possible initial position thereof and the corresponding connection position through an are having an amplitude of 3730 in the reverse direction.

8. An electric connection device as claimed in claim 1, including a shield having a projecting annular flange, and wherein the guiding means for coupling the plug to the receptacle are constituted by a lug carried by the plug casing and cooperate with a slot formed in said projecting annular flange of said slhield whilst the insulating support of the receptacle is stationarily fixed within its casing and the insulating support of the plug is adjustable for orientation with respect to said lug, the projecting annular flange of the shield is provided on the face directed towards the receptacle with a plurality of notches uniformly spaced at intervals of 15, one of said notches being intended to be opened at the moment of assembly so as to constitute the guiding slot.

LOCKING DEVICES FOR MOVABLE PIN-SHAPED ELECTRICAL CONTACTS BACKGROUND OF THE INVENTION This present invention relates to a locking device for mobile pin shaped electric contacts.

Electrical connection devices for household and industrial equipment generally consist of plug members, including variously shaped pins which slide with various degrees of friction into corresponding socket members. In this type of connection, contact between the plug and socket is very often mediocre, even in arrangements in which a slit is provided in the pins to give them some elasticity since the elasticity very often deteriorates due to the strain to which the pins are subjected through normal use. Moreover, faulty contacts have a tendency to generate radio-electric strays.

Attempts have been made to overcome these disadvantages by increasing the dimensions of the members. However, in spite of this, they reach high temperatures which might be dangerous for safety.

SUMMARY OF THE INVENTION An object of this invention is to remedy these inconveniences. One advantage of this invention is in the fact that the insertion and removal of the plug is effortless, due to the provision of a lever which controls the contact pressure between the plug and the socket.

In the device according to the invention, increased contact pressure is achieved which results in a very noticeable increase in admissible current density for the same pin section without noticeable temperature rise. This allows'the size of the plug to be reduced and yet increases its capacity. The pins may be made of cold drawn brass for current quality, and of berylium bronze for higher quality, for example.

For safety reasons, the increase in the contact pressure may be limited to a value in which emergency re moval of the plug is possible without having to reduce the pressure by movement of the lever.

Another advantage of the invention is that it enables miniature plugs for electric razors, for example, to be BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 represents a cross section view of a current P FIG. 2 represents a cross section view of an alternative of a plug FIG. 3 represents a cross section taken along the line A-A of FIG. 2.

FIG. 4 represents a cross section taken along the line B-B of FIG. 2

FIG. 5 represents another alternative of a plug FIG. 6 represents a fourth alternative of a plug FIG. 7 represents a plug with automatic tightening and loosening.

FIG. 8 represents a cross section of a conducting portion of the cam used in the plug of the present invention FIG. 9 represents the tightening lever used in the present invention equiped with a fuse FIG. 10 is an end view of a female plug with limited elastic deformation FIG. II is a cross section view of the plug of FIG. 10

FIG. 12 represents another alternative of an outside tightening plug FIG. 13 shows the cross section taken along the line A of FIG. 12

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 represents an electrical plug according to the present invention which includes a body 1 which sup ports a pair of pins 2 and 3 a portion of each of which are adapted to extend within a corresponding female socket (not shown) for completing an electrical eonneetion. The pin 2 is fixed relative to the body 1 and supports a tightening screw 5 for the electrical conductor 6. The pin'3 is fulcrummed about a boss 4 formed on the pin 2 under the action of a cam 7 mounted in the body 1 and engaging an end portion of the pin 3. The cam 7 is operated by a lever 8 which is pivotally mounted to the body 1 for movement between a position shown in the solid lines in which the cam acts on the pin 3 in a manner to force the free end portion of the pin away from the pin 2 to tighten the connection with the socket, and a position shown in the dashed lines in which this force is relaxed. In this manner the plug is easily inserted or removed from the socket with the lever 8 in the position shown in the dashed lines, while the contact pressure between the pins 2 and 3 and their corresponding members in the socket can be increased by moving the lever to the position shown in the solid lines.

According to the embodiment of FIG. 2, two pins 9 and 10, formed ofa conducting material such as metal, are mounted in the body 15 with their free end portions projecting therefrom and adapted to extend in the eavity 11 of the socket 12. A screw 13 is supported by the body 15 and is adapted to engage and secure a conductor 14. The pin 9 is fixed relative to the body 15 by means of a boss having an opening 16 therein for receiving a tab 17 integral with the pin 9. The pin 9 is in contact throughout its outside surface portion with the inner wall of the socket 12 and is provided with a tightening screw 18 for securing a conductor 19. The other end portion 20 of the pin 10 is bent in a manner to extend between two bosses formed in the body 15, and a lever 21, having a cam 22 fixed thereto, is pivoted relative to the body 15 about a point 23. The cam 22 engages the pin 10 to rock same between a tightening and 4 loosening position about a contact point 24 to move the free ends of the pins 9 and 10 away from each other and increase the contact pressure against the inner wall of the socket 12 in the area 25.

FIGS. 3 and 4 represent cross sections AA and BB of FIG. 2. The cavity 11 in the body 12 of the female plug tightens on the half pins 9 and 10 which in the portions introduced into the cell 11, are in the shape of a half UNITED STATES T PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 853378 Dated December 10, 1974 Inventor (s) ARMEL LOUIS Itis certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 15, delete "shows the and add is a-.

Column 3, line 1, delete "and in" and add and which in the portions within the body 15 are of a-. Column 3, line 8 delete "the fulcrum 31 of".

Signed and sealed this 20th day of May 1975.

(SEAL) Attest:

C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks 

1. A plug device for engaging a cooperating receptacle for transferring electrical current, said plug device comprising a housing, at least one pair of pins supported by said housing, with end portions of both pins in each pair projecting from said housing and being adapted to extend in the same opening in said receptacle, one pin of each pair being fixed relative to said housing, a cam rotatably mounted relative to said housing and engaging said other pin, and lever means for rotating said cam and urging said end portion of said other pin about a fulcrum point in a direction away from said end portion of said one pin to increase the contact pressure with the walls defining said opening in said receptacle.
 2. The device according to claim 1 further comprising means for connecting an electrical conductor to one of the pins of each pair.
 3. The device of claim 1 wherein there aRe two pairs of pins, the end portions of one pair adapted to extend in one opening in said receptacle and the end portions of the other pair adapted to extend in another opening in said receptacle.
 4. The device according to claim 1 wherein said first pin is adapted to establish said fulcrum point. 